@Test public void testSubtractFrom() { double[] vals1 = {1, 2, 3, 4, 5, 6, 7, 8}; DoubleVector vec1 = new DenseDoubleVector(vals1); double constant = 10; DoubleVector vec3 = vec1.subtractFrom(constant); for (int i = 0; i < vals1.length; ++i) { assertEquals(constant - vec1.get(i), vec3.get(i), 0.000001); } }